The invention relates to a method to form a rail joint, in which staggerings corresponding to each other are made in joinable solid-profile rail ends of parts of a rail so that when a completed rail joint is seen from above the rail heads bond; both rail ends are secured to corresponding mountings; the rail ends secured to the mountings are brought against each other whereby said bonding is established; and the mountings that are against each other are secured to each another. The invention additionally relates to a rail joint made with this method.
Such a rail joint is used, for example, in main supports of a crane, which are made of two or more blocks, which are joined at the final assembly site by a flange-strap joint. Typically, the part between the rail blocks of the crane car is welded at the final assembly site, and the mating surfaces are finished and painted after the assembly. The finishing work on a rail requires special skills, special tools and time, which has to be taken into account at the time the delivery schedule and resources are planned. Furthermore, the finishing work during final assembly is often expensive special work under demanding conditions, such as a tight schedule, working on top of high structures, temporary working levels, organising hot work permits, the weather in outdoors installation work, etc.
In case the rail joint itself is not welded, it is staggered between two blocks so that the bearing wheel of a truck, travelling along the rail moves from one block to the next as smoothly as possibly. It is difficult to implement the welding of a staggered rail to the mounting with adequate support and firmness for the rail.
In a prior art method, to make a rail joint, beams acting as the mountings for the rails to be joined are first brought end-to-end, and joined by means of bolts at the sides of the beams. The ends of the rails to be joined, mounted on the joined beams, are located at a distance from the beam joining edges. A separate rail piece is placed between the rail ends which are apart and to be joined, which is welded to the rail ends to be joined from above by fill welding. Then, the bolted joints combining the beams and rails are opened, the beams are moved apart, the root of the joined rail is welded, the welded joint is tidied up, and the dismantled bolted joints are joined anew. This solution is most laborious and furthermore provides an unsatisfactory solution both from the viewpoint of the functioning and durability of the rail joint.
Based on publication WO 2012/034895 A9, a joining method is known for rail ends of an open-profile capsular rail, in which jointing sleeves parallel to the rail are welded to the sides of the ends of the rail segments to be joined. The segments are joined end-on-end with bolts through the jointing sleeves without a welded joint. This method meant for rail joints in open-profile rails with lighter loads is not suitable for joints in solid profile rails because it does not allow a strong enough and faultlessly operating rail joint to be achieved for more heavy-duty applications that require solid profile rails.
Also known is a staggered rail joint referred to initially, in which the staggering continues evenly from the top to the bottom of the rail ends to be joined in the rail joint, whereby both rail ends staggered all the way down are welded to a mounting having even edges, by the half of the staggering that in any one case extends to the edge of the mounting, whereas the half of the staggering which is further from the edge of the mounting rests freely on the mounting. This solution produces a reasonably good end result, but even here the load is neither evenly distributed at the joint nor is it not stable enough in long-term use.